According to this blog post by Microsoft Windows 10 will start rolling out for Insiders on July 29. Reserved devices not registered on the Insider Program will get the upgrade at a later date after fine tuning the OS.
Starting on July 29, we will start rolling out Windows 10 to our Windows Insiders. From there, we will start notifying reserved systems in waves, slowly scaling up after July 29th. Each day of the roll-out, we will listen, learn and update the experience for all Windows 10 users.
According to this blog post by Microsoft Windows 10 will start rolling out for Insiders on July 29. Reserved devices not registered on the Insider Program will get the upgrade at a later date after fine tuning the OS.